1. Field of the Invention
This invention pertains to safety devices, and more particularly to apparatus for enhancing the safety of mobile storage systems.
2. Description of the Prior Art.
Mobile storage systems are well known. They are becoming increasingly popular in offices, factories, and warehouses because of their ability to store large quantities of materials in a minimum amount of space.
The design of a mobile storage system involves several safety considerations. A characteristic of the system movable carriages is that they normally are quite high and long in relation to their widths in the direction of travel along the system rails. Consequently, a top loaded carriage may be relatively unstable and prone to tipping in the directions of motion.
Carriage anti tip devices are known, such as the device disclosed in co-pending U.S. patent application Ser. No. 694,847 now U.S. Pat. No. 4,618,197. Although the prior anti tip devices are generally satisfactory, under certain operating conditions it is possible for a moving carriage to lurch to one side of the rails such that the anti tip device becomes disengaged. Further, prior anti tip devices having components fixedly mounted to the carriages require component assembly to the carriages prior to assembly of the carriage to the rails. Consequently, the carriages must be assembled to the rails by sliding the carriages along the rails from one end, which is an inefficient operation.
It is also known to employ end stops attached to the mobile storage system rails for limiting carriage travel along the rails. U.S. patent application Ser. No. 766,249 illustrates exemplary carriage stops. Prior stops, however, are fixed to the rails to permanently limit the end position of the carriages. Changing the travel limits to suit subsequent system modifications is therefore a costly and time consuming operation.
Another significant safety aspect of mobile storage systems is the temporary locking of the carriages in place on the rails. Ability to lock the carriages in selected places is important for the safety of persons in the aisles between adjacent carriages. Locking ability is also desirable for retaining a carriage in one location for extended periods of loading or unloading the shelves. A prior locking device is disclosed in U.S. patent application Ser. No. 575,216 now U.S. Pat. No. 4,607,896. Although that device has enjoyed commercial success, it is somewhat more expensive than desired.
Thus, a need exists for improved safety features on mobile storage systems.